Description: Thallus crustose, often almost entirely hidden in the substrate, sometimes thinly episubstratic and rimose, appearing as a greyish white to olive brown patch. Medulla I-. Apothecia lecideine (0.1-)0.2-0.3(-0.5) mm across, soon sessile, with a black, epruinose, at first flat then soon convex disc, and a thin, soon excluded proper margin. Proper exciple narrow, poorly differentiated, aethalea-type, the inner hyphae hyaline, prosoplectenchymatous, the outer hyphae parallel and usually strongly brown-pigmented; epithecium brown, N-; hymenium colourless, 35-60 µm high, not inspersed with oil droplets; paraphyses simple to moderately branched, apically swollen, with a brown pigment cap; hypothecium dark reddish brown. Asci 8-spored, clavate, Bacidia-type. Ascospores 1-septate, soon brown, ellipsoid with obtuse ends, not constricted at septum, 6-10(-12) x 2.5-4(-4.5) µm, Buellia-type, thin-walled throughout, the wall not ornamented. Pycnidia often numerous, globose, unilocular. Conidia very short, oblong to ellipsoid, some of them almost globose, 1.5-3 x 0.5-1(-1.4) µm. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a mainly cool-temperate to boreal-montane, circumpolar species found on acid bark, especially of conifers, and on wooden poles in upland areas, to be looked for further in the mountains of southern Italy.